h1 {
    text-align: center;
    margin: 100px auto;
    color: yellowgreen;
}

body {
    background-color: pink;
}

* {
    padding: 0;
    margin: 0;
}

h4 {
    width: 400px;
    height: 400px;
    font-size: 60px;
    color: green;
    background-color: #ccc;
}